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Mantella crocea
Mantella crocea is a species of average-sized Mantella native to central-eastern Madagascar. It is a moderately toxic species and fairly bright in coloration. Its populations have declined dramatically in the last 30 years, possibly due to a combination of habitat loss, infection with chytridiomycosis, and illegal exportation for the pet trade. It is thought to be the sister species of M. viridis. Poison Mantella crocea produces pumiliotoxin, a potent nerve poison manufactured and stored in subcutaneous membranes and secreted through a modified layer of epidermis. M. crocea, while not the most toxic of the Mantellas, is still a highly toxic animal. The very small amount of poison the frog possesses is still enough to make a human ill. Like most Mantellas, however, M. crocea will only release its poison if it feels that it is threatened, and wild specimens can be handled if the human holding it is calm and relaxed. As with all other Mantellas and poison dart frogs, M. crocea loses its toxicity in captivity due to a change in diet. This has led scientists to believe that pumilio actually takes its poison from the ants it feeds on. Pumiliotoxin is deadly in high concentrations. Pumiliotoxin is weaker than allopumiliotoxin and especially batrachotoxin, with a lethal dose of 2 mg (M. crocea carries about half a milligram). There are three different types of this toxin A, B and C. Toxins A and B are significantly more toxic than C. Pumiliotoxins affect the body because they interfere with muscle contraction in the heart and skeletal muscle. The toxin works by affecting the calcium channels. Some of the symptoms of pumiliotoxins are partial paralysis, having difficulty moving, being hyperactive and in some cases it can result in death. Description Mantella crocea is an average-sized Mantella. Male specimens reach 2.2 centimetres in length from snout to vent, but the females are larger, reaching 2.5 centimetres long. Females are typically bulkier than males and have a more pronounced arch in their backs. However, the difference in size and back shape can be very slight, making M. crocea one of the more difficult Mantellas to sex. M. crocea is somewhat similar to the Green Mantella, Mantella viridis. It is always primarily a light yellowish-brown in coloration, and stands out against the mosses on which it frequently sits. The flanks and sides of the face are black, with the ventral surfaces being yellow with circular or elliptical patches of black. The limbs and dorsum are yellowish-brown or dirty yellow. Mantella crocea, like most Mantellas, is bold and often makes little attempt to conceal itself. If threatened, it will either climb trees or dissapear under the leaf litter. If cut off from any form of escape, it relies on its poison for protection. Reproduction Mantella crocea has a similar reproductive cycle to most other Mantellas. At the beginning of the rainy season, gatherings of M. crocea gather around suitable breeding sites. As the rain starts falling, males begin to call to females with a sound that has been described as like pebbles clicking together. Males are unusually peaceful, establishing breeding spaces only by calling, with wrestling being uncommon compared to other Mantellas. Larger and more powerful males are more popular among females, and females may grapple to mate with a single male. Once a pair has joined, the male leads the female to a vertical surface such as a tree trunk or a boulder. The female lays her eggs on the vertical surface, and the male then fertilizes them. They are then guarded by the male, who will protect the eggs and moisten them with his own urine. When the eggs hatch, the tadpoles form a tight ball around the waist of their father, who carries them to a puddle on the forest floor and guards them until their development is complete. The froglets are then led by the male to an existing group. Category:Mantellas Category:Pet amphibians Category:Fauna of Madagascar Category:Endemic fauna of Madagascar